This invention relates to a safety device for use in a motor vehicle and, in particular, to a device for immediately shutting down the engine of a motor vehicle in the event the throttle linkage breaks or becomes jammed in a position other than idle.
As noted in detail in U.S. Pat. Nos. 3,695,379 to Veilleux and 3,487,183 to Schulman, electrical devices have heretofore been installed in the throttle mechanism of motor vehicles to shut down the engine ignition in the event the throttle return spring breaks or becomes disconnected when the engine is running. For the most part, these devices use a spring loaded shut-off switch which is wired into the ignition system of the engine and is arranged to pull against the return spring through an appropriate linkage to hold the switch closed. If the return spring fails for some reason, the switch spring is released and the switch is cycled to an opened condition thereby shutting down the engine.
These devices work very well for their intended purposes, however, they are incapable of shutting down the engine in the event that the throttle linkage becomes jammed in an open position. The jammed linkage will prevent the spring from being released and the switch will remain open despite the fact that the linkage has failed in an open position. This type of open throttle failure is one of the most dangerous situations faced by race car drivers. Under racing conditions, the throttle usually becomes jammed when the car is travelling at a high rate of speed. The driver invariably is too occupied in maintaining control of the vehicle to manually switch off the ignition.